Despite marked reductions in cigarette smoking in the general population, smoking rates among economically disadvantaged women have increased. Smoking among women of reproductive age is a concern because in addition to the usual health risks, they face additional risks should they become pregnant. Research indicates that economically disadvantaged women respond to low nicotine content cigarettes (VLNCCs) with reductions in smoking rates, cigarette demand, dependence severity, and other measures of addiction. The goal of this project is to evaluate whether increased availability and appeal of an alternative non-combusted nicotine source (e-cigarettes) will enhance the effectiveness of a reduced-nicotine standard for cigarettes in socioeconomically disadvantaged female smokers of reproductive age. Study aims are: (1) to compare the effects of normal nicotine content cigarettes (NNCCs) alone, VLNCCs alone, VLNCCs + tobacco-flavored e-cigarettes, and VLNCCs + preferred-flavor e-cigarettes on total number of cigarettes per day; (2) to compare the effects of the four study conditions on cigarette demand, smoke exposure (breath carbon monoxide), and tobacco carcinogen biomarkers (NNAL, PAH metabolites); (3) to explore the effects of the four study conditions on cerebral blood flow, other measures of brain function and structure, and airway inflammation; and (4) to explore the effects of the four study conditions on abstinence-induced cigarette demand, craving, and withdrawal. In this study, 212 disadvantaged female smokers (ages 18-44) will be randomized to 16 weeks of: (1) NNCCs alone (the control condition); (2) VLNCCs alone; (3) VLNCCs + nicotinized tobacco-flavored e-cigarettes; or (4) VLNCCs + nicotinized preferred-flavor e-cigarettes. Participants will complete two in-person assessments (involving baseline health and smoking assessments, a variety of questionnaires, biomarker assessments, cognitive functioning tests, and functional MRI) and use an interactive voice response system to report daily product use and nicotine withdrawal symptoms. After 16 weeks of use, participants will undergo an abstinence assessment in which researchers will examine the effects of the study conditions on participants’ ability to abstain from cigarettes and their responses to abstinence. Findings may inform regulatory activities related to reduced-nicotine cigarettes.